refactor: remove code smell java:S5786 (iluwatar#2159)

https://sonarcloud.io/organizations/iluwatar/rules?open=java%3AS5786&rule_key=java%3AS5786

Author: robertvolkmann

acyclic-visitor/src/test/java/com/iluwatar/acyclicvisitor/ConfigureForDosVisitorTest.java

@@ -74,7 +74,7 @@ void testVisitForHayes() {
 
   @BeforeEach
   @AfterEach
-  public void clearLoggers() {
+  void clearLoggers() {
     TestLoggerFactory.clear();
   }
 }

acyclic-visitor/src/test/java/com/iluwatar/acyclicvisitor/ConfigureForUnixVisitorTest.java

@@ -44,7 +44,7 @@ class ConfigureForUnixVisitorTest {
 
   @BeforeEach
   @AfterEach
-  public void clearLoggers() {
+  void clearLoggers() {
     TestLoggerFactory.clear();
   }
 

adapter/src/test/java/com/iluwatar/adapter/AdapterPatternTest.java

@@ -48,7 +48,7 @@ class AdapterPatternTest {
    * This method runs before the test execution and sets the bean objects in the beans Map.
    */
   @BeforeEach
-  public void setup() {
+  void setup() {
     beans = new HashMap<>();
 
     var fishingBoatAdapter = spy(new FishingBoatAdapter());

aggregator-microservices/aggregator-service/src/test/java/com/iluwatar/aggregator/microservices/AggregatorTest.java

@@ -48,7 +48,7 @@ class AggregatorTest {
   private ProductInventoryClient inventoryClient;
 
   @BeforeEach
-  public void setup() {
+  void setup() {
     MockitoAnnotations.openMocks(this);
   }
 

api-gateway/api-gateway-service/src/test/java/com/iluwatar/api/gateway/ApiGatewayTest.java

@@ -48,7 +48,7 @@ class ApiGatewayTest {
   private PriceClient priceClient;
 
   @BeforeEach
-  public void setup() {
+  void setup() {
     MockitoAnnotations.openMocks(this);
   }
 

business-delegate/src/test/java/com/iluwatar/business/delegate/BusinessDelegateTest.java

@@ -49,7 +49,7 @@ class BusinessDelegateTest {
    * execution of every test.
    */
   @BeforeEach
-  public void setup() {
+  void setup() {
     netflixService = spy(new NetflixService());
     youTubeService = spy(new YouTubeService());
 

caching/src/test/java/com/iluwatar/caching/CachingTest.java

@@ -39,7 +39,7 @@ class CachingTest {
    * Setup of application test includes: initializing DB connection and cache size/capacity.
    */
   @BeforeEach
-  public void setUp() {
+  void setUp() {
     // VirtualDB (instead of MongoDB) was used in running the JUnit tests
     // to avoid Maven compilation errors. Set flag to true to run the
     // tests with MongoDB (provided that MongoDB is installed and socket

callback/src/test/java/com/iluwatar/callback/CallbackTest.java

@@ -34,7 +34,7 @@
  * <p>
  * Could be done with mock objects as well where the call method call is verified.
  */
-public class CallbackTest {
+class CallbackTest {
 
   private Integer callingCount = 0;
 

circuit-breaker/src/test/java/com/iluwatar/circuitbreaker/AppTest.java

@@ -34,7 +34,7 @@
 /**
  * App Test showing usage of circuit breaker.
  */
-public class AppTest {
+class AppTest {
 
   private static final Logger LOGGER = LoggerFactory.getLogger(AppTest.class);
 
@@ -60,7 +60,7 @@ public class AppTest {
    * and retry time period of 2 seconds.
    */
   @BeforeEach
-  public void setupCircuitBreakers() {
+  void setupCircuitBreakers() {
     var delayedService = new DelayedRemoteService(System.nanoTime(), STARTUP_DELAY);
     //Set the circuit Breaker parameters
     delayedServiceCircuitBreaker = new DefaultCircuitBreaker(delayedService, 3000,
@@ -78,7 +78,7 @@ public void setupCircuitBreakers() {
   }
 
   @Test
-  public void testFailure_OpenStateTransition() {
+  void testFailure_OpenStateTransition() {
     //Calling delayed service, which will be unhealthy till 4 seconds
     assertEquals("Delayed service is down", monitoringService.delayedServiceResponse());
     //As failure threshold is "1", the circuit breaker is changed to OPEN
@@ -93,7 +93,7 @@ public void testFailure_OpenStateTransition() {
   }
 
   @Test
-  public void testFailure_HalfOpenStateTransition() {
+  void testFailure_HalfOpenStateTransition() {
     //Calling delayed service, which will be unhealthy till 4 seconds
     assertEquals("Delayed service is down", monitoringService.delayedServiceResponse());
     //As failure threshold is "1", the circuit breaker is changed to OPEN
@@ -112,7 +112,7 @@ public void testFailure_HalfOpenStateTransition() {
   }
 
   @Test
-  public void testRecovery_ClosedStateTransition() {
+  void testRecovery_ClosedStateTransition() {
     //Calling delayed service, which will be unhealthy till 4 seconds
     assertEquals("Delayed service is down", monitoringService.delayedServiceResponse());
     //As failure threshold is "1", the circuit breaker is changed to OPEN

circuit-breaker/src/test/java/com/iluwatar/circuitbreaker/DefaultCircuitBreakerTest.java

@@ -31,7 +31,7 @@
 /**
  * Circuit Breaker test
  */
-public class DefaultCircuitBreakerTest {
+class DefaultCircuitBreakerTest {
 
   //long timeout, int failureThreshold, long retryTimePeriod
   @Test